How to improve the network transmission rate is an issue to be addressed in communication field. In indoor situations, e.g., public transportation or offices, it can typically deploy a small base station to improve the quality of signals for users and to extend the network coverage. However, in order to support the accesses of various network operators' end users, it is required for the network operators to deploy their own small base station in a limited space to serve the users, but this will significantly increase the cost of deployment and the difficulty of installation.
Therefore, there is a need to provide a communication method capable of supporting network sharing of multiple network operators.